1. Good Morning! Please sit at your lab table with you lab notebook.

2. Biology
Study of life

3. Is it ALIVE?
Biology is the study of life, but how can you tell if something is alive?
All living organisms exhibit certain properties that biologists look for to classify it as alive.

4. Properties of Life Reproduction Cells Homeostasis Metabolism Heredity
All living organisms have the following properties present at some point in their life:
Cells
Reproduction
Homeostasis
Metabolism
Heredity
Evolution
Interdependence

5. Lets start small…
What are we made of?

6. Water Expands when frozen Water is essential for life
Living organisms are made mostly of water
70%-90%
Resistant to temperature change
Homeostasis
Expands when frozen
Less density than l form
Turnover in lakes

7. Water Adhesive (adhere to surfaces) Cohesive (adhere to each other)
The universal solvent
Water can dissolve ions and polar molecules. Non-polar molecules do not dissolve well in water (oil, fats). Remember like dissolves like (polar dissolves polar, non-polar dissolves non-polar).

8. Adhesion
Because water molecules are polar, they have a tendency to stick to other polar substances.
Glass may carry a partial charge along its surface.
That’s why rain droplets stick to windows.

9. Why does water have these special properties???

10. …because water is POLAR!
Polar molecules have uneven charges.
This attracts ions and other polar molecules
It is also the reason water is a universal solvent

11. Capillary Action Polarity
water uses cohesive and adhesive properties to climb up capillaries in plants
This makes it possible for the tops of the trees to obtain water

12. Chemistry of Life The Essential Ingredients for Life

13. Ingredients for Life
Water
Carbohydrates
Lipids
Proteins
Nucleic Acids

14. Carbon Compounds Organic (carbon) compounds are found in living things
Carbon has four valence electrons ready for bonding
Carbon can form chains, chains with branches or rings

15. What does it all mean???

16. Carbon can bond with itself and with many other elements
Form large organic molecules called biomolecules
Small chains are called monomers
Large chains made of monomers are called polymers

17. Carbon
Monomer
Polymer

18. Carbon forms:
Carbohydrates
Lipids
Proteins
Nucleic Acid

19. Carbohydrates
- made of Carbon, Hydrogen and Oxygen in 1:2:1 ratio (C6H12O6)
- major source of energy found in most foods
- monosaccharides are simple sugars and the building block of carbohydrates (glucose and fructose)
- polysaccharides are large molecules made of many sugars that store energy.
plants – starch animals - glycogen

20. Carbohydrate - Sugar
Monosaccharide– glucose
polysaccharide- starch

21. Lipids non-polar molecules
Is it soluble in H2O?
- fats, phospholipids, steroids, oils, waxes…
- important part of cell membranes
- lipids are used by cells for energy storage
- Insulation

22. Lipids
Saturated fatty acid – no double bonds between carbon- carbon bonds, straight molecule, solid at room temperature
Unsaturated fatty acid – double bonds that make the molecule kinked, liquid at room temperature

23. The way a protein folds is important to its function
Proteins - Amino Acids
There are 20 different amino acids
Amino Acids bonded together form a chain called a polypeptide chain.
Amine Group: -NH2
A polypeptide chain folds into a protein
The way a protein folds is important to its function
Mad Cow Disease

24. Functions of Protiens Transport: hemoglobin in red blood cells
Movement: muscles
Structural: membranes, hair, nails
Enzymes: cellular reactions

25. Enzymes Enzymes are proteins Speed up chemical reactions
Lower activation energy
They work on a specific substrate
Some reactions in your body would not occur without enzymes.

26. Nucleic Acids – Long chains of nucleotides (sugar, phosphate, base)
Contain genetic/heredity information in code
- DNA- (deoxyribonucleic acid) found in nucleus of cells. Have genes that contain hereditary info (traits). 2 strands
- RNA – (ribonucleic acid) can act as an enzyme or help in protein synthesis. 1 strand

27. Nucleic acids – Genetic Material
Nucleic acids are composed of long chains of nucleotides

28. Identifying Organic Compounds Lab

29. Introduction
The most common organic compounds found in living organisms are lipids, carbohydrates, proteins, and nucleic acids.
Substances called indicators can be used to test for the presence of organic compounds. An indicator is a substance that changes color in the presence of a particular compound. In this investigation, you will use several indicators to test for the presence of lipids, carbohydrates and proteins in various foods.

30. Materials For each organic compound test you need: 5 drops egg white
5 drops lettuce/water
5 drops apple juice
5 drops corn oil
5 drops Spinach/water
5 drops peanut butter
5 drops potato/water
5 drops water
Starch test: Iodine solution
Sugar test: Benedicts solution
Protein: Biuret solution
8 Test tubes
Test tube holder
Test tube rack
Hot plate
Brown paper towel
Labeling tape

31. Lipid Test
1. Divide a piece of brown paper towel into 8 equal sections. In each section, write the name of one test substances, as shown.
2. In each section, place a small drop of the identified food onto the brown paper towel. With another paper towel, wipe off any excess pieces of food that may stick to the paper. Set aside for minutes
3. Hold paper to light or window. If food sample produces a translucent or see-through spot, there is a presence of a LIPID.
1.Distilled Water
2.Egg White
3.Corn Oil
4. Spinach
5.Peanut Butter
6.Apple Juice
7.Potato & Water
8.Fish

32. Carbohydrate Test - Starch
1. Label test tubes: water, egg, oil, Spinach, peanut, apple, potato, fish
2. Add 5 drops of each food sample to its proper test tube.
3.Add 5 drops of iodine solution to each test tube and shake.
*Iodine will change color from yellow brown →blue black in presence of STARCH.
4. Record data on table.
5. Wash test tubes thoroughly!

33. Carbohydrate Test - Sugar
1. Set up hot water bath: Fill half the beaker with tap water and heat to a gentle boil.
2. While water bath is heating, fill each cleaned test tube with 5 full drops of the appropriate food sample.
3. Add 10 drops of Benedicts solution and shake.
4. Place test tubes in hot water bath and heat for 3-5 minutes.
5. Caution: Remove test tubes from water bath with test tube holder!
*When heated, Benedicts solution will change color from blue → green, yellow, orange, or red in the presence of SUGAR.
6. Record any color changes on data table.
7. Wash test tubes thoroughly!

34. Protein Test
1. Put 5 drops of appropriate food samples in each labeled test tube.
2. Add 5 drops of Biuret solution to each test tube and gently shake.
Caution: Biuret contains NaOH, a strong base. If you splash any on yourself, wash with water and notify your teacher immediately!
*Biuret changes color from light blue→blue-violet in the presence of PROTEIN.
3. Record any color change on data table.
4. Wash test tubes thoroughly!

35. Data chart All should have before and after descriptions!
Food Sample
Lipid
Test
Starch
Sugar
AA or Protein Test
Egg white
Corn Oil
Potato
Peanut Butter
Water
Apple Juice
Fish
Spinach